Door lock



8. KOVACS DOOR LOCK Oct. 23, 1928.

Filed Feb. 24, 1927 2 Sheets-Sheet INVENTOR B. KOVACS DOOR LOCK Filed Feb. 24, 1927 2 Sheets-Sheet 2 a -.a4 J6 (MW 0 J3 BY 5 fig ATTORNY Patented Oct. 23, 1928. i

UNITED STATES BENJAMIN KOVACS, OF-NEW BRUNSWICK, NEW JERSEY.

' DOOR LOCK.

' Application filed February 24, 1927'. "Serial'No.'170,539.

.-The presentinvention relates to improvements indoor locks and more-particularly to looks oftha-t type wherein 'the locking bolt is controlled by two sets of tumblers,eachset oftumblers beingoperatedby aseparate key;

One of-the objects of the invention is to generally simplify the construction of locks of this t e-and to so 'design 'theesc'utfcheon plate thereof that the keyhole forreceiving one of the keys is concealed and has the gen era l=appearance of a single keyhole lock es'cutcheon plate. I Another object of the invention is to com bine with the lock anele'etric' alarm such a manner that a bell is set in action when the lockin'g bolt of thelock is retracted from its locking position. With these and other objects in View; which will more fully appear as the nature of the invention is-better understood, thesame consists in-the combination; arrangement and construction of parts hereinafter described, pointed outin theappended claims and il-' lustr'ated in the accompanyingdrawings, it being understood 'tha-t'niany changes may be made in the-size and proportion otthe several parts and details of construction Within the scope of the appended claims, W-'itl10ut departing from the spirit or sacrificingany of the advantages of the invention.

One of the many possible embodiments of the'invention is illustrated in the accompany- Iing drawings, in which Fi ure 1 is an elevation of the oute'rface of a oor, showing the improved lock in posi tion thereon ;Fig. 2 is an elevation of the inner face of'thedoorwith the lock in position thereon; Fig. 3 is an elevation of the lock with the bolt projected and the ca plate removed, toshowthe interior parts; Fg. 4 is also an elevation of the lock, the cap plate be- --ing attached thereto; Fig. 5 is'a section-taken on line 5 5 of Fig. 3, thecapplate'being in position on the lock Fig. 6 is an elevation of one of the keyhole linings; Fig. 7 is a diagram ofthe-electric circuit of thealannteature of the lock;-Fig. Sis-an elevation of a keeperco-operating Withthe locking bolt;

andFig. 9 is asectiontakenonline 9-9. of

r8; 7 i i i n the drawings, the numeral 10indifcates a lock casing and the numeral 11 thec'over plate thereof. In the casin'g areformed holes 12, through whichexten cl screws 13, tor -at= taching the said-easing tfiith interface are not. interchangeable.

when it is desired to project the bolt into,

locking position or toTetr'act same from suchpositionf 'The said key may be inserted into the lock bothfrom the outside and from the inside." For this purpose the casingfland the cap plateare provided with registering keyholes' 25 and26;respectively. The keyhole' 26 is surroundedby a keyhole lining 27,

which is riveted or otherwiseattached to the cap plate' and is; preferably, inade of twvo sections 28 and 29,'vvhich areadjustably secured together gby a 'screW530. This adjustm'ent is necessary in order to faccommodate the said lir eyh'oleflining t'od'o'ors ofjvarying' thicknesses. The keyhole lining is disposed Within'a' keyhole 31 in the door',t he said keyhole re'gistering' fwith the holes 25 and 26 abovementioned. 5

The tumbler 19 has made integral there- "with a downwardly extending projection 32, which is disposed in the path of the key, so thattheilugs 21'may be diseng'aged fromthe notches 22 in thelockingbolt; to permit the .saidbolt to be shifted into locking and retracted-po'sitions, a's-the casemay-be.

Ontheflocking boltis formed-an arm 33, provided on its free end Witha pin 34,'adapted toenter s1ots135* in afset ofspring-pressed tumblers 36, which are pivoted'at 37 tothe lockfcasing. lh islot s35 are out ofialignmen't vv-ith'thejsaid pijn'whenithe locking bolt is in its projected position, shown in 3 of the drawings, and such casethesaid set of tumblers Te StSI PQI a Stop 38 within the lock casing. The tumblers" 36 arejactuated by a key; entering the said casing-from the outside through a keyhole 39 the Cap platell said keyhole being providedvvith a liningfiO of the type above" described 1 and disposed in a key- "holei411 in the door. The two keysare of different configurati ns that is to say they are .herefore, n order to unlock the door, two keys are necessary. The key co-operating with the keyhole 39 1s so designed that, upon giving the same one half of a revolution, the tumblers 36 are lifted around their pivot 37 to bring the slots 35 thereof into alignment with the pin 34 on the arm 33 of the locking bolt.

For the purpose of lifting the tumblers 36 from the inside, a lever 42 is pivoted at 43 to the outer face of the lock easing. To this lever is fixed a pin 44, extending through a slot 45 into the lock casing and being adapted to co-operate with projections 46 on the tumblers 36, as clearly shown in Fig. 3 of the drawings. The pin 44 is disposed in the path of the projection 23 of the tumbler 19, (see Fig. 3).

The lever 42 is made of metal and is in electric contact with the metallic lock casing. The said lever is provided outside of the lock casing with a metallic knob 47, preferably a frustum of a cone, adapted to co-operate with a metallic contact member 48, hinged to a base plate 49, the latter being mounted upon but insulated from the lock casing. Normally the contact member 48 and the knob 47 are out of contact, as shown in Fig. 5 of the drawings. The said contact member and knob are included in an electric circuit 50, containing a battery 51 and a bell 52. The wire leading from one terminal of the battery, and denoted in Figs. 3 and 4 of the drawings by the numeral 53, is in electric contact with the lock casing, while the wire leading from one of the terminals of'the bell, and denoted in Figs. 3 and 4 of the drawingsby the numeral 54, is in electric contact with the base plate 49.

To the outer surface of the door is attached an escutcheon plate 55 of any suitable eonfiguration and design. This escutcheon plate is provided with two keyholes 56 and 57, the keyhole 56 registering with the keyholes 25 and 26, and the keyhole 57 being in alignment with the keyhole 39. The keyhole 57 is normally covered by a slide 58, pivoted at 59 to said escutcheon plate. This slide is so shaped and designed that it merges into the design of the escutcheon. plate, so that persons not familiar with the lock would have the impression that it is operable by a single key only, that is to say by a key insertable through the visible keyhole 56 in the escutcheon plate.

lVith the locking bolt co-operates a keeper 60, shown in Figs. 8 and 9 of the drawings. This keeper is fastened by screws 61 to the door j amb 62 and is made of two elements 63 and 64, adjustably secured together by screws 65. These elements are so constructed that a slot 66 is formed within the same, into which the locking bolt above referred to is adapted to enter. The width of this slot may be widened by unscrewing the screws 65 from the element 63 and moving the element 64 outwards. In order to keep the elements in adusted positions, shims may be inserted between the said two elements. It is obvious that, while herein a keeper of special design has been described, any other may be used without departing from the invention, which lies mainly in the lock construction above described.

The operation of the improved lock is as follows: Let us assume that the locking bolt is in its projected position and the other elements of the lock are in the positions shown in the several figures of the drawings. In order to retract the locking bolt from the outside, first the slide 58 must be shifted so as to uncover the keyhole 57. A key is then inserted into the said keyhole and given onehalf of a turn so as to lift the tumblers 36 to bring the slots 35 therein into alignment with the pin 34 on the arm 33 of the locking bolt. A second key is then inserted into the keyhole 56. The first half of a turn of this key causes disengagement of the tumbler 19 from the locking bolt 15, and a continued movement of the key retracts partly the locking bolt from the keeper, the pin 34 entering the slots 35 in the tumblers 36. The tumbler 19 drops back into notches in the locking bolt 15, but is disengaged from these notches during the second turn of the key, so that the locking bolt may be entirely withdrawn from the keeper. As the tumbler 19 is raised, its projection 23 engages the pin 44 of the arm 42 and raises the said arm, thereby bringing its knob 47 into electric contact with the contact member 48. The electric circuit is thereby closed and an alarm sounded. A person being inside of the room may retract the locking bolt by lifting the arm 42, whereby its pin 44 comes in contact with the projections 46 on the tumblers 36, so that the slots 35 there in are brought into alignment with the pin 34. A key is then inserted through the keyhole 25 and. the lock operated in the manner above described. Of course, in such case the alarm need not be operated. In order to prevent sounding of the alarm, the contact member 48 is swung around its hinge onto the base plate 49.

If a person attempts to pick the look by means of a key or other instrument inserted through the keyhole 26, it is obvious that the locking bolt cannot be retracted because its pin 34 is brought into abutment with the proj ections 46 on the tumblers 36. i

For the purpose of projecting the locking bolt 15, only that key is necessary which cooperates with the said locking bolt, the tumblers 36 being forced by the spring co-operating therewith into their lower positions, shown in Fig. 3 of the drawings, as soon as the pin 34 is disengaged from the slots 35 in the tumblers 36.

What I claim is:

In a lock, the combination with a casing, of a locking bolt slidable therein, a tumbler co-operating with said bolt, an arm pivoted i (l t) ill) to said casing provided with a pin in the path of said tumbler, a metallic contact membcr fixed to said arm, a second metallic contact member normally disengaged from said first-mentioned contact member mounted upon and insulated from said casing, said contact members forming part of an electric circuit, the contact member on said arm being shifted into contact With said second-men- 10 tioned contact member when said tumbler is actuated for the purpose of disengaging the same from saidlocking bolt, said second-mentioned contact member being hinged to said casing so as to permit the same to be shifted out of the path of said first-mentioned contact member.

Signed at New York, in the county of New York and State of New York, this 29th day of January, A. D. 1927.

v BENJAMIN KOVAGS. 

